Remagnetizing device



March 30, 1937. R A. CHEGWIDDEN ET AL 2,075,504

REMAGNETIZING DEVICE Filed April 21, 1936 /NVEN7'ORS R. A. CHE GW/DDE N$.J. HARAZ/M J.J. KUHN I. C. PETT/T Patented Mar. 30, 1937 UNITED STATESPATENT OFFICE REMAGNETIZING DEVICE New York Application April 21, 1936,Serial No. 75,602

4 Claims.

This invention relates to remagnetizing devices, and more particularlyto a remagnetizing device for telephone ringers equipped with permanentmagnets.

In such ringers after a certain length of time in use it is necessary toremagnetize the permanent magnets, which heretofore necessitated thedisconnecting and removal of the ringers from their associated telephoneapparatus and the sending of such ringers to the shop, which incurredconsiderable expense.

The object of the invention is to provide a device for remagnetizing thepermanent magnets used in telephone ringers in the field which will besimple, cheap to manufacture, convenient in use and positive inoperation.

According to the invention a permanent magnet of cast-cobalt steel and aset of soft steel pole-pieces which rest against the ends of the cobaltsteel permanent magnet serve to make contact with the ends of the ringermagnet for remagnetizing it. More specifically, the invention consistsin providing the ends of a horseshoeshaped magnet, for example, withpole-pieces having means for engaging the ends of a ringer magnet at aplurality of points for remagnetizing it without removing such a magnetor any of the ringer operating parts from their supporting backboard.Qne of the pole-pieces is rigidly secured to one end of theremagnetizing magnet while the other pole-piece is mounted for slidingmovement for adjustment to take care of variations in length of theringer magnets, means being provided for guiding the movable piece andfor limiting its sliding movement under the action of a retractingspring, which also serves for holding the pole-pieces on the magnet tobe reenergized with a predetermined contact pressure.

Other novel features of the invention will appear from the followingdescription and by the claims appended thereto, reference being had tothe accompanying drawing in which:

Fig. 1 is an assembly view of the remagnetizing device shown in positionon the permanent magnet of a telephone ringer, the remagnetizing deviceand the telephone ringer being shown in perspective;

Fig. 2 is a partial view of the remagnetizing magnet showing thepole-pieces in engaged relation with the permanent magnet of the ringer,one of the pole pieces being shown partly in section and showing itssecuring screw engaging the ends of the remagnetizing magnet; and

Fig. 3 is a side view taken along the line 3-3 of Fig. 2 and looking inthe direction indicated by the arrows.

As shown in Fig. l of the drawing, the construction of the ringer towhich the remagnetizing device of the invention is particularly welladapted for use but which forms no part of the invention consists of acover Y which is hinged to the backboard support YI to form with thecover Y a housing for the ringer device. In the ringer device per se, MMindicates electromagnets, m a mounting plate for securing theelectromagnets at one end, a a yoke secured to the other ends of themagnets MM and serving for pivotally mounting the armature A. M is apermanent magnet, a a rod, and a the clapper for engaging the gongs G inresponse to the energization of the electromagnets.

In the remagnetizing device of the invention, as shown in the drawing, Iis a horseshoeshaped permanent magnet made of cast-cobalt steel. To theend X of permanent magnet III is mounted a soft steel pole-piece II,which is securely held thereon by a screw I2 shown in Fig. 2. Thepole-piece II is provided with oppositely disposed channel-shapedgrooves I3 and I4 for receiving the prongs I5 and I6 formed at the endof an angle piece II of on-magnetic material which is secured to a softsteel pole-piece I8. This pole-piece is held against the end XI ofpermanent magnet III by magnetic attraction and is guided in itsmovement away from and toward the pole-piece II through the engagementof prongs I5 and I6 of angle piece H in the grooves I3 and I4 ofpole-piece II, pole-pieces II and I8 being formed at their free endswith angular recesses ml and r2 registering with the ends of the ringermagnet.

A spring I9 which is hooked at one end to a stud 20 carried by thepole-piece II and its other end to a stud 2| carried by the pole-pieceI8 serves for holding the pole-pieces I I and I8 with a predeterminedcontact pressure on the permanent magnet M to be remagnetized by theremagnetizing magnet II] when placed in position as shown in Figs. 1 and2. The movement of pole-piece I8 toward the pole-piece II when theremagnetizing device of the invention is not in use is limited by theengagement of abutting portion 22 at the free end of bar H with thepolepiece II.

The pole-piece I8 is formed with a substantially V-shaped groove 23 forreceiving the hammer rod a of the ringer as shown in Fig. 1.

In using this device the pole-piece I8 is moved against the resistanceof spring I9 9. distance sufiicient to permit the engagement of thepolepieces H and i8 on the magnet M to be remagnetized as shown in Figs.1 and 2. This tool provides for remagnetizing telephone ringers Withoutremoving them from their supports, without removing any of theircooperating parts and with no discontinuance of the operation of thetelephone apparatus to which such a ringer is connected, thus effectingconsiderable economy in the repair of telephone ringers.

What is claimed is:

1. A remagnetizing device consisting of a permanent magnet, a set ofsoft steel pole tips resting against the ends of said magnet and adaptedto make contact with the poles of the magnet to be remagnetized, and afork-shaped tie bar secured at one end to one pole tip and connected bya helical spring to the other pole tip.

2. A remagnetizing device for the permanent magnets of ringers,comprising a horseshoeshaped magnet, a pole-piece secured to one end ofsaid magnet, a pole-piece arranged for sliding movement on the other endof said magnet, a bar of non-magnetic material secured to one of saidpole-pieces and extending toward the other end of the remagnetizingmagnet in engageable relation with the first-mentioned polepiece toserve as guide for the slidable pole-piece, and spring means foryieldably holding the polepieces on the ends of the ringer magnet to beremagnetized.

3. A remagnetizing device for the permanent magnets of ringers,comprising a horseshoeshaped permanent magnet, an angular pole-piece ateach end of said magnet, each of said polepieces having shoulder andparallelly extending portions registering with the ends of the ringermagnet, one of said pole-pieces being slidable on one end of theremagnetizing magnet, and a spring acting on said slidable pole-piecefor engaging said pole-pieces with the ringer magnet with apredetermined contact presstu'e.

4. A remagnetizing device for the permanent magnets of ringers,comprising a remagnetizing permanent magnet having its ends extendingsubstantially in parallel relation to each other, a pole-piece securedto one end of said magnet having a channel-shaped groove on two oppositesides thereof and a portion for engaging one end of the ringer magnet,another pole-piece, a guiding member of non-magnetic material for thelast-mentioned pole-piece having a plurality of means engaging thegrooves in the other of said pole-pieces, and a spring having one endconnected to the secured pole-piece and its other end to the movablepole-piece for holding said pole-pieces with a predetermined contactpressure on the ends of the magnet to be remagnetized.

RAYMOND A. CHEGWIDDEN. STANLEY J. HARAZIM.

JOHN J. KUHN.

IRVING C. PETTIT.

